Multifunctional Carbon Fibre Composite Battery

With the rapid increase in electric-powered vehicles and wearable electronics, there is a growing demand for lightweight energy storage systems. Currently, electric energy is stored in dedicated batteries that need to be protected against mechanical loading and the environment, which will likely evolve from a single external device to an integrated structural, flexible and wearable materials. Herein, the research aimed to develop multifunctional carbon fibre composite batteries to simultaneously store electrochemical energy and with the ability of loadbearing, which can be structurally rigid or flexible to accommodate various applications and needs. The significant contributions of the research are: 1) The multifunctional performance of carbon fibre based positive/negative electrode was investigated for structural lithium-ion batteries. Lithium cobalt oxide coated carbon fibre electrode using a slurry coating method demonstrated excellent electrochemical performance, while the active material coating was well-adhered on the carbon fibres substrate, allowing the mechanical loads to be transferred through the interlayers. The fabricated electrode indicated excellent resistance to delamination between the coating and the carbon fibre layer. 2) A novel two-step curing process to fabricate a multifunctional structural Zn-MnO2 battery was demonstrated. This approach utilised the epoxy matrix to encapsulate the composite energy storage while the carbon fibres served as structure reinforced layers and current collectors simultaneously. The electrodes were fabricated by using a hydrothermal synthesis for MnO2 and electrodeposition for Zn, respectively. The structural composite battery manifested practical energy density and cycling durability, which illustrated a new pathway to integrate the batteries into the system level. 3) A novel MnO2-vertical graphene-Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) cathode was developed for flexible batteries towards wearable electronic devices. The as-assembled Zn-MnO2 flexible battery demonstrated excellent electrochemical stability under several mechanical tests and achieved excellent energy densities of 400.2 Wh kg-1 with high power densities of 0.68 kW kg-1. This work demonstrated a new route for developing next-generation Zn-MnO2 batteries for future flexible high-performance electronic devices. Finally, ongoing research and future recommendation of multifunctional carbon fibre composite batteries were discussed